May is a month of traditions: of flowers and commencements, of the Kentucky Derby for 117 years and Indianapolis five-hundred-mile races for 81. For an automobile race, Indy is ancient. Back in 1911, it was an all-day affair, as the winner covered five hundred miles in six hours and forty-two minutes. These days winners complete the distance in less than three hours, the same oval unraveling for a driver with the same turns, banks, and exhilarating straights. Everything has been tried in American auto racing in nearly one hundred years, from unabashed blood sport to fine competition—to the delight of manufacturers, promoters, and drivers. And fans. With so much choice and change, fans are the great governing board in American racing, creating some traditions, like Indy, to last.